Lessons in clinical reasoning - pitfalls, myths, and pearls: shoulder pain as the first and only manifestation of lung cancer.

OBJECTIVES: Lung cancer is the leading cause of cancer-related death and poses significant challenges in diagnosis and management. Although muscle metastases are exceedingly rare and typically not the initial clinical manifestation of neoplastic processes, their recognition is crucial for optimal patient care. CASE PRESENTATION: We present a case report in which we identify the unique scenario of a 60-year-old man with shoulder pain and a deltoid muscle mass, initially suggestive of an undifferentiated pleomorphic sarcoma. However, further investigations, including radiological findings and muscle biopsy, revealed an unexpected primary lung adenocarcinoma. We performed a systematic literature search to identify the incidence of SMM and reflect on how to improve and build on better diagnosis for entities as atypical as this. This atypical presentation highlights the importance of recognizing and addressing cognitive biases in clinical decision-making, as acknowledging the possibility of uncommon presentations is vital. By embracing a comprehensive approach that combines imaging studies with histopathological confirmation, healthcare providers can ensure accurate prognoses and appropriate management strategies, ultimately improving patient outcomes. CONCLUSIONS: This case serves as a reminder of the need to remain vigilant, open-minded, and aware of cognitive biases when confronted with uncommon clinical presentations, emphasizing the significance of early recognition and prompt evaluation in achieving optimal patient care.

Ataxia of Charlevoix-Saguenay: MR and Clinical Results in Lower-Limb Musculature.

OBJECTIVE: Peripheral neuropathy is a cardinal manifestation of the autosomal recessive spastic ataxia of Charlevoix- Saguenay (ARSACS), although its type of neuromuscular involvement has not been definitely established, and magnetic resonance imaging (MRI) plays an important role in the assessment of muscle and nerve diseases. The objective of this work has been to define the patterns of muscle weakness and of abnormal muscular MRI in ARSACS. PATIENTS AND METHODS: Five patients with a molecular diagnosis of ARSACS, aged 39 to 59 years, whose electrophysiological findings were consistent with an axonal neuropathy of distal distribution superimposed on a developmental defect of myelinization, underwent neurological and MRI lower-limb examinations. Conventional FSE T1-weighted and STIR sequences were performed, looking for fatty infiltration and oedema in the musculature of the thighs, legs and feet, together with their distribution along the longitudinal axis of the muscle bellies. RESULTS: On clinical examination, paralysis was apparent in foot muscles; moderate weakness, in leg musculature; and normal strength, in thigh muscles. MRI demonstrated massive fat deposition in the foot muscles and medial gastrocnemii in every case, distal fat infiltration and oedema in every leg muscle group, and preservation of thigh muscles, albeit with diffuse minimal non-specific fat infiltration. An inverse correlation between strength and degree of fat infiltration in lower-limb muscles became apparent. CONCLUSION: The preponderance of weakness and MRI abnormalities in distal muscle groups was concordant with the presence of a length-dependent axonopathy, as described in ARSACS.Ataxie de Charlevoix-Saguenay : IRM et observations cliniques au niveau de la musculature des membres inférieurs.

[Bilateral calcifying tendinitis of the long tendon of the biceps associated with a SLAP lesion]. / Tendinitis calcificante bilateral del tendón largo del biceps asociado a lesión SLAP.

Calcifying tendinitis is a common disorder related to deposition of hidroxyapatite crystals, which is most common around the shoulder joint, involving the supraespinosus tendon. It can however, affect almost any tendon at its insertion. Clinical features are variable and include pain and inflammation that often resolves spontaneously. We present a case of bilateral calcifying tendinitis of the long head of the biceps tendon at its insertion on the superior glenoid rim associated with superior labrum antero-posterior tears (SLAP) confirmed by arthroscopy. Calcium deposits were surgically removed and the SLAP lesions were repaired.

Fournier's gangrene in a 44-year-old woman: CT scan findings.

OBJECTIVES: To show standard CT findings and their diagnostic usefulness in female patients suffering from Fournier's gangrene. METHOD/RESULT: A woman who had undergone a previous lateral internal sphincterotomy presented to the emergency department with severe pain in the hypogastrium and perianal region; physical examination revealed an induration in the left buttock. CT images showed an abscessed collection in the rectovaginal space and gas in the levator ani muscle, left ischiorectal fossa and the root of the left thigh. CONCLUSIONS: CT scan is considered an excellent diagnostic tool in the management of patients with Fournier's gangrene, as it shows both the origin of the infection and its extent.

Gangrena perineal en mujer de 44 años. Hallazgos en Tomografía Axial Computarizada (TAC) / Fournier´s gangrene in a 44-year-old woman: CT scan findings

OBJETIVOS: Mostrar los hallazgos característicos en TAC y su utilidad diagnóstica en la gangrena de Fournier en mujeres.METODO/RESULTADO: Mujer con antecedentes de esfinterotomía lateral interna que acude a urgencias por intenso dolor en hipogastrio y en región perineal con endurecimiento del glúteo izquierdo. En la TAC se observa una colección abscesificada en el espacio rectovaginal y gas en músculos elevadores del ano, fosa isquiorrectal izquierda y en raíz del muslo izquierdo(AU)

OBJECTIVES: To show standard CT findings and their diagnostic usefulness in female patients suffering from Fournier’s gangrene.METHOD/RESULT: A woman who had undergone a previous lateral internal sphincterotomy presented to the emergency department with severe pain in the hypogastrium and perianal region; physical examination revealed an induration in the left buttock. CT images showed an abscessed collection in the rectovaginal space and gas in the levator ani muscle, left ischiorectal fossa and the root of the left thigh.CONCLUSIONS: CT scan is considered an excellent diagnostic tool in the management of patients with Fournier’s gangrene, as it shows both the origin of the infection and its extent(AU)

Lipoma arborescente de la bursa bicipital / Lipoma arborescens of the bicipital bursa

El lipoma arborescente (LA) es una entidad benigna caracterizada por la proliferación de tejido graso de morfología vellosa en la capa subsinovial, que afecta habitualmente a la rodilla. A continuación se presenta un caso de LA en la bursa bicipitorradial del codo en una mujer de 44 años. A pesar de la rara localización de la lesión, los hallazgos radiológicos en la ecografía y la resonancia magnética permitieron el diagnóstico (AU)

Lipoma arborescens is a rare benign entity characterized by proliferation of villous fat tissue in subsynovial layer that usually affects the knee joint. We report a case of lipoma arborescens in bicipitoradial bursa of the elbow in a 44 year-old female patient. In spite of this rare location, radiographic findings by ultrasonography and magnetic resonance imaging made diagnosis possible (AU)

Fenómeno de vacío en la bursa iliopsoas como posible fuente de error diagnóstico radiológico / Vacuum phenomena in iliopsoas bursa: a possible pitfall at CT and MR imaging

El fenómeno de vacío es una alteración conocida en las articulaciones osteoartríticas. En ocasiones puede verse gas en las bursas adyacentes a las articulaciones debido a la existencia de una comunicación con la articulación. Presentamos un caso de fenómeno de vacío en la bursa iliopsoas en asociación a una cadera osteoartrítica sobre la base de una displasia acetabular en una mujer de 48 años que acudió a nuestra consulta con sospecha inicial de absceso de iliopsoas.

Vacuum phenomena is a well-known alteration in osteoarthritis. It´s possible to see gas in bursas around osteoarthritic joints due to comunication between them. We describe an unusual case of vacuum phenomena arising within an enlarged iliopsoas bursa in association with mildly osteoarthritic and dysplastic hip in a 48-year-old woman who underwent radiologic study in our institution with an initial suspiction of iliopsoas abscess.

[Lipoma arborescens of the bicipital bursa]. / Lipoma arborescente de la bursa bicipital.

Lipoma arborescens is a rare benign entity characterized by proliferation of villous fat tissue in subsynovial layer that usually affects the knee joint. We report a case of lipoma arborescens in bicipitoradial bursa of the elbow in a 44 year-old female patient. In spite of this rare location, radiographic findings by ultrasonography and magnetic resonance imaging made diagnosis possible.

CYP3A5 3, CYP3A4 1B and MDR1 C3435T genotype distributions in Ecuadorians.

Polymorphisms in CYP3A genes, such as CYP3A5} and CYP3A4, as well as in the MDR1 gene, which encodes for P-glycoprotein, have been implicated as genetic markers in several disorders. Differences in the frequency distribution of the allelic variants CYP3A5 3, CYP3A4 1B, and MDR1 3435T have been demonstrated between distinct ethnic groups. In this study we examined the frequency of these allelic variants in 317 healthy Mestizo individuals from Ecuador and made comparisons with results reported in the literature. The genotypes were determined by PCR-RFLP. Allele and genotype differences were studied by chi-square test. The MDR1 T allele frequency was similar to that of Spaniard or Asian populations, which is consistent with the ethnic origin of Ecuadorian Mestizo individuals (Amerindian and Spaniard Caucasians). By contrast, the CYP3A5 3 allele frequency was significantly lower in Ecuadorians than in Spaniards and other white populations and higher than in Central Americans, Asians and blacks. CYP3A4 1B was more common in Ecuadorians than in Caucasian or Asian populations but less present than in blacks. The differences in the polymorphism found in this work should be considered in allele-disease association studies.

Growth hormone does not alter CYP2A6 activity in growth hormone-deficient children.

A large number of metabolic alterations are increasingly being treated with growth hormone. Despite the fact that growth hormone is known to be the main regulator of several hepatic drug metabolizing enzymes in rodents, few studies deal with the effect of growth hormone on hepatic enzyme activities in human beings. The aim of this study was to determine the effects of growth hormone replacement therapy for 4 weeks on CYP2A6 activity in children, because changes in this enzyme activity may have important therapeutic and toxic consequences. A total of 31 growth hormone-deficient children (age range 4.1-13.1 years; mean age 9.88 +/- 2.89 years) participated. The genotypes of CYP2A6 gene, CYP2A6*1A, CYP2A6*1B, CYP2A6*4, CYP2A6*1x2 and CYP2A6*9, were determined by polymerase chain reaction. To assess the enzyme activity, we used caffeine as a probe drug at two points in time: before starting growth hormone therapy (Day 0) and after 4 weeks of growth hormone therapy (Day A). Caffeine and metabolite concentrations in urine were assayed by high-pressure liquid chromatography. The metabolite ratio 1,7-dimethilxanthine to 1,7-dimethylurate (17U/17X) served to indicate CYP2A6 activity. Median value and 95% confidence interval at baseline was 1.08 (0.98-1.24). The value after treatment was 1.08 (0.86-1.21). Data comparison between periods showed lack of statistically significant differences (P > 0.05). The relative change, measured by the ratio of medians and 90% confidence interval, was 1.02 (0.84-1.19). There were no significant differences when the ratio between genotype groups were compared. These results indicate that growth hormone replacement therapy of growth hormone-deficient children for 4 weeks does not modify the CYP2A6 activity and hence the efficacy or toxicity of the CYP2A6 substrate compounds.

Lack of effect of growth hormone replacement therapy on CYP1A2 and xanthine oxidase activities in growth hormone-deficient children.

BACKGROUND AND OBJECTIVES: The recombinant human growth hormone (rhGH) is being increasingly used for a number of metabolic alterations. GH is the main regulator of several hepatic drug metabolizing enzymes in rodents. In addition, GH could play a major role in defining the interface between pharmacogenetics and development. However, little is known about the effect of GH on the activity of hepatic enzymes in children. The aim of this study was to determine the effect of rhGH replacement therapy for 4 weeks on CYP1A2 and xanthine oxidase (XO) activities in children. METHODS: We used caffeine as a probe drug to assess the enzyme activities at two points in time: before starting GH treatment (day 0) and after 4 weeks on rhGH therapy (day A). A total of 31 GH-deficient children (age range: 4.1-13.1 years, mean age: 9.88+/-2.89 years) participated. Urinary concentrations of caffeine and metabolites were determined by high-performance liquid chromatography (HPLC) to calculate the metabolite ratios: (AFMU+1X+1U)/17U for CYP1A2 and 1U/(1X+1U) for XO. RESULTS: Four weeks of GH substitution did not importantly alter the markers of the enzyme activities measured in this study. Median values and 95% confidence intervals (CI) at baseline were 5.17 (3.87-5.59) for the CYP1A2 ratio and 0.62 (0.56-0.65) for the XO ratio. These values, after treatment, were 4.57 (3.90-5.97) for the CYP1A2 marker and 0.62 (0.59-0.67) for the XO ratio. Data comparison between periods showed lack of statistically significant differences (P>0.05). The relative changes measured by the ratios of medians and 90% CI were 1.14 (0.90-1.31) and 0.99 (0.94-1.06) for CYP1A2 and XO, respectively. CONCLUSIONS: The absence of significant changes in the markers of enzyme activities CYP1A2 and XO suggests that rhGH replacement therapy of GH-deficient children for 4 weeks could not noticeably modify the efficacy or toxicity of substrates of these metabolic enzymes.